1. Field of Invention
The invention relates to a display panel and a display device and, in particular, to a display panel and a display device having an enhanced transmittance.
2. Related Art
With the progress of technologies, flat display devices have been widely applied to various kinds of fields. Especially, liquid crystal display (LCD) devices, having advantages such as compact structure, low power consumption, less weight and less radiation, gradually take the place of cathode ray tube (CRT) display devices, and are widely applied to various electronic products, such as mobile phones, portable multimedia devices, notebooks, LCD TVs and LCD screens.
In the multi-domain vertical alignment (MVA) process for enhancing the quality of the TFT LCD, the polymer stabilized vertical alignment (PSVA) technology is a sufficiently mature technique to achieve the mass production and enhance the optical features such as aperture ratio and contrast. In the PSVA technology, photosensitive monomers are mixed with the liquid crystal during the one drop filling (ODF) process, and then an ultraviolet exposure is executed while an electric field is applied, so that the photosensitive monomers within the liquid crystal are cured. Consequently, the cured monomers are arranged according to the pattern of the pixel electrode of the TFT substrate so that the LC alignment can be achieved by the photocured monomers.
For the same illuminance, a display panel with a higher transmittance can save more power for the display device. Therefore, the industry strives to increase the transmittance of the display panel to save more energy and enhance the product competitiveness. In the conventional art, the pattern of the pixel electrode generally includes trunk electrode and branch electrode, and the included angle between the branch electrode and a horizontal direction is designed as 45 degrees, and thereby the average azimuthal angle (so-called ψ angle) of the liquid crystal molecules corresponding to the branch electrode can be controlled at 45 degrees so that they display panel can have a higher transmittance. However, with the higher resolution, i.e. higher ppi value, of the display panel and the smaller size of the pixel, the average azimuthal angle of the liquid crystal molecule will be affected by the electric field of the adjacent data line, common electrode and transparent electrode and thus can't be kept at 45 degrees anymore, and therefore the transmittance of the display panel will be reduced.